The Methodology and Data Management Core has been critically important to the success of the Northwestern University MAMDC and its EEHSR Component in particular, and is critically important to this MCRC. The centralized availability of expertise in database and study form construction-, data entry, monitoring, and retrieval; and the various analytic techniques used to test hypotheses and control for potential confounders are essential resources for all investigators. The Core has assisted educators, epidemiologists, and health services researchers from several divisions and departments in studying a wide variety of disease and demographic groups including systemic lupus erythematosus, osteoarthritis, juvenile dermatomyositis (JDMS), rheumatoid arthritis, and the elderly. Core resources have been used efficiently because of the economies of scale. Recognizing that newer analytic techniques have become available and more accepted, this proposal continues the expansion of our work in clinical epidemiology and health services research implemented during the current MAMDC cycle. Given this Center's emphasis on longitudinal outcomes research, experts in advanced statistical techniques (generalized estimating equation (GEE), classification and regression trees (CART), meta-analysis), economics, decision analysis, clinical epidemiology and behavioral science are included as Core investigators. The Core will support the three full proposals and the one developmental/feasibility proposal in this grant application and the funded activities of the JDMS registry at Children's Memorial Hospital. It will continue to contribute to the MCRC research environment by providing data management and methodologic assistance to investigators who engage in arthritis related research. The participation of Core investigators in the arthritis clinical research conference and enhanced viability and support for clinical epidemiology and health services research on Northwestern University's Chicago Campus further heighten the Core's influence on the environment.